This weekend we have the next North American Ironman in the 2014 Qualification season – Ironman Arizona. From an age group perspective it’s a typical US Ironman race with a broad and relatively even spread of results from front-of-pack Kona qualifiers through to those finishing close to 17 hours. It also has the usual 50 slots for the Ironman World Championship with the M40-44 age group taking the largest share.

First let’s compare the finisher distributions from 8 years in Arizona with the distribution produced by looking at all the North American races of 2012. This amalgamation of results will lose the detail of individual races, but shows some general patterns. In the latest version of these graphs I’ve added dotted lines indicating the 5th, 10th, 25th and 50th percentile time for each discipline. The differences between the two charts are subtle, but the percentile markers do show one or two areas where Arizona may tend to be slightly faster – swim and bike. Differences are small in race terms and account for minutes in the overall results.

I can also drill down and compare finishing splits at an age group level of Ironman Arizona’s past results. In most age group of reasonable size the pattern tends to reflect that of the whole field, but we can use the percentile lines again to help compare across groups. Unsurprisingly we can observe that there is a general decline in finish times with age, although considering the 30-50 age range the 8 year data may not fully reflect current trends.

Certainly if I utilise my recent charts looking at the change in Ironman performance in the age groups we can see that most age groups predominantly show trends towards faster times for placings. As I’ve previously noted these trends are not necessarily significant, although the degree of change appears steeper – in many cases – than displayed in my analysis of Florida. Focussing on the red top 20 positions while times again appear to be getting faster the changes are generally smaller. Still times do appear to be slowly falling.

Returning to a longer standing chart and comparing the median splits between Arizona 2005-2012 and all 2012 NA Races reflects the observations made for the distributions. Swim and bike medians are slightly faster for the age groups in Arizona while the run is similar. The pattern for the pros is not quite the same with the male performances being broadly comparable, perhaps just a little slower in the female field, but not significantly different over 9 hours of racing.

Predicted Kona Slot Allocation for Ironman Arizona 2013

Number of Athletes

Number of Slots

F18-24

10

1

F25-29

69

2

F30-34

114

2

F35-39

141

2

F40-44

154

3

F45-49

147

3

F50-54

99

2

F55-59

33

1

F60-64

14

1

F65-69

4

1

M18-24

34

1

M25-29

146

2

M30-34

240

3

M35-39

330

4

M40-44

486

6

M45-49

372

5

M50-54

291

4

M55-59

115

2

M60-64

55

2

M65-69

22

1

M70-74

3

1

M80+

1

1

Total

2880

50

As usual I’ve used the Bib list available on Ironman.com to construct the above distribution of Kona slots and as usual exact numbers will be determined by the actual start numbers on race day.

The final set of graphs (I promise). An updated version of the top 20 performances charts. This new format plots the average finish time and the Kona slots as before, but also shows the individual finish times form past results. This makes outliers more obvious than the previous range bars and also gives some indication where the weighting of results lies in comparison to the average.

For the men the averages indicate 9:30s below the age of 40 although it should be noted that results within qualification have ranged by a full hour in the last 8 years. Above 40 moves the goal post towards 10:00, but once again with the caveat on the range of times that have made the top 5 or 6 in the age groups. For the women, with fewer slot available and podium placings required it can prove harder to estimate on the basis of an average. As a rough guide 10:30 may do it below the age of 40 and an 11:00 for those just over.

What happens this weekend will come down to conditions and the athletes who turn up on the day. If the trends are to be believed then we might expect qualification to be faster than average, but if conditions are tough it may turn things around.

Results will be analysed, but not until December. On race morning Gill and I will be boarding a plane to Jamaica for our honeymoon. Ironman stats will be strictly off the cards.